Description: A virtual deduction elimination rule. (Contributed by Alan Sare, 24-Jun-2011) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypotheses | e200.1 | |- (. ph ,. ps ->. ch ). |
|
e200.2 | |- th |
||
e200.3 | |- ta |
||
e200.4 | |- ( ch -> ( th -> ( ta -> et ) ) ) |
||
Assertion | e200 | |- (. ph ,. ps ->. et ). |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | e200.1 | |- (. ph ,. ps ->. ch ). |
|
2 | e200.2 | |- th |
|
3 | e200.3 | |- ta |
|
4 | e200.4 | |- ( ch -> ( th -> ( ta -> et ) ) ) |
|
5 | 2 | vd02 | |- (. ph ,. ps ->. th ). |
6 | 3 | vd02 | |- (. ph ,. ps ->. ta ). |
7 | 1 5 6 4 | e222 | |- (. ph ,. ps ->. et ). |